The Torre della Gabbia (Tower of the Cage) rises above the Piazza delle Erbe next to the Rotonda di San Lorenzo, and is one of Mantua's most unsettling medieval relics. Built in the 13th century, the tower derives its name from the iron cage suspended near its summit — a form of public punishment in which convicted criminals were exposed to the elements and the scrutiny of the market crowd below.
The cage is still there, rusting and slightly sinister against the Mantuan skyline. It is not open for climbing but is best seen from the piazza below, particularly in the afternoon light when the ironwork is clearly visible against the sky. The contrast between the market bustle of the piazza and the grim cage overhead makes it one of those details that stays with you.